Multiple stage separator



Oct. 14,1958 G. M. MElsEL ETAL 2,856,070

MULTIPLE STAGE sEPARAToR Filed Feb. 7, 1955 5 sheets-sheet 1 Georgev M. Meise/ Dona/d J. ,Drinkwater Robe/ff 0. Gribble BY Y v ATTORNEYS Oct. 14, 1958 G. M. Ml-:lsELET/Al. 2,856,070 f MULTIPLE STAGE SEPARATOR Filed Feb.' 7, 1955 s sheets-'sheen 2 INVENTORS George M. Meise! Dnald J, Drinkwater Robert 0. Grbble ATTORNEYS MULrlrLn STAGE sEPARAroR George M. Meisel, Denver, Colo., Robert Q. Gribble, Chisholm, Minn., and Donald J. Drinkwater, Denver, Colo., assignors to Colorado Iron Works Company, a corporation of Maine Application February 7, 1955, Serial No. 486,406

i 7 Claims. (Cl. 209-39) This invention relates to ore classifying apparatus and more particularly to classifiers especially equipped for separating the solids of a mixture of magnetic and nonmagnetic ore suspended in a carrier fluid, and to processes of treatment of such ore pulps.

The device ofthe present invention provides an improved apparatus for separating the magnetics of an ore pulp from the non-magnetics, and for dewatering the resultant non-magnetic or magnetic material. The apparatus provides an integral magnetic separator and a mechanical classifying unit. The device, further, provides means for separating the magnetic material from a pulp, and means for deslirning and dewatering non-magnetic or magnetic solids of said pulp. The apparatus is useful for materials in which certain portions may be reclaimed by magnetic means, and which includes such separations as magnetic from non-magnetic products, heavy media recovery, and the like. ln certain processes of ore treatment, the non-magnetics or magnetics are deslimed and dewatered by mechanical classifiers wherein the underflow or coarse product is recovered as a substantially dewatered product, and the slimes are discarded as waste with the water.

The unit may be used in various `circuits for the beneficiation of ores, and for various purposes in such circuits. In one type of beneficiation circuit it may be used to recover separated magnetics from non-magnetics as where strongly magnetic material is recovered from the less or substantially non-magnetic material, e. g., separation of magnetite, roasted hematite, limonite and siderite from gangue; franklinite from zincite, and similar separations. The unit may be used before a classifier in a circuit to make magnetic separations and subsequently classify, deslime and dewater the magnetic concentrate or the nonmagnetic underflow; or for recovery of heavy media, where the heavy media is magnetic, in which instances the unit also serves as a surge tank and, also, provides means for returning into the circuit stored the heavy media, when the pool density must be increased in the operation of the heavy media separator.

Included among the objects and advantages of the present invention is a device for separating magnetic materials from a pulp of magnetic and non-magnetic materials suspended in a carrier liquid, and a process for performing such separations. Novel control means are provided for insuring efiicient operation of the apparatus for effective separation of the ingredients of the ore pulp. The apparatus, furthermore, provides a magnetic separation and a classification, desliming and dewatering zone which may be separately controlled for optimum effectiveness without impairing the operation of the entire unit.

These and other objects and advantages of the invention may be more readily `ascertained by referring to the following description and appended illustrations, in which:

Fig. 1 is a side elevational view of a device according to the invention;

2,856,070 Patented Oct. 14, 1958 ice Fig. 2 is a partial top plan view showing the relation of the major components of the unit according to the invention;

Fig. 3 is a cross sectional view of a portion of the device taken along section line 3 3;

Fig. 4 is a partial elevational view of another portion of the device taken along section line 4 4;

Fig. 5 is a modified device according to the invention; and

Fig. 6 is a top plan View of the device of Fig. 5.

In the device illustrated in Figs. l and 2, a classifier tank, generally shown by numeral 10, comprises a pair of substantially upright sides 12 and 14 and an end plate 15. The tank includes a sloping bottom 16 which extends from the lowest point of the tank to a point above the level of the pool contained in the tank. A spiral iiight conveyor 17 secured to a drive shaft 18 and driven by a drive 19 slowly rotates in the tank to convey settled solids up the inclined bottom 16 of the tank of the contained pool. A lifting device or hoist 20 is secured to the lower end of the drive shaft 18 for raising and lowering the spiral flight conveyor in the tank. Adjustable overflow weirs 21 are disposed on each side of the tank and provide means for adjusting and maintaining the pool level 22 of the tank, and provide an overflow for fines, slime and water from material fed into the tank. Magnetic separators 24, 25 and 26 are mounted on the sides of the spiral flight, mechanical classifier, and the magnetic discharge or the non-magnetic discharge, depending on the particular operation, is passed into the spiral classifier. As illustrated, a magnetic separator is mounted on each side of the pool, however, they may be mounted on the same side or on the pool end. The magnetic separators may be of the permanent magnetic or electromagnetic type.

ln one effective application of the device according to the invention, a right-hand magnetic drum separator 24 is a counter-current electro-magnetic separator, while the left-hand separator 26 is a concurrent permanent magnetic separator. In this case, ore pulp is fed to the two magnetic drum separators which separate the magnetic material from the pulp, and the resultant non-magnetic pulp is discharged into the spiral classifier below the surface of the pool of a spiral fiight mechanical classifier. The non-magnetic solids are heavy and sink to the bottom of the classifier, and are subsequently conveyed up along the sloping bottom 16 to a dewatering deck 23, the length of which is controlled by adjustment of the overflow Weirs 21. These deslimed solids are dewatered and then discharged, while the slimes and the water flow over the overflow weirs of the classifier tank.

The concurrent magnetic separator 26 includes a rubber-covered separator drum 30 and a replaceable tray 31 spaced from and adjacent the lower part of the drum. The tray substantially envelops the drum and extends over the lower part of the periphery thereof. On one end of the tank in which the drum operates there is a slat weir 34 which is one of the means of controlling the separator water line between a maximum lever 33a and a minimum level 33b, which correspond to the upper and lower limits of the slat weir. By adding or removing one or more of the slats of the slat Weir, the water level of the separator may be primarily adjusted. With all of the slats of the Weir 34 in place the drum will operate in the high water lever 33a, while with no slats in the weir' the drum will operate in the low water line 33h. The slat weir discharges into an overflow launder 36 which discharges into the classifier tank. A feed box 37 having a dead bed bottom 38 is mounted on the opposite side of the tray 31. Feed from the feed box 37 enters a feed launder 39 extending substantially along the length of the drum, and the feed passes from the launder through the space between the drum 30 and the replaceable tray 31. Feed from the feed box 37 passes into launder 39 and it is distributed along the replaceable tray 31. The magnetic material of thejfeed which comes in contact with the drum, between the tray 31 and the drum Sil, is picked up in fields of magnets 40 internal of the drum, and the magnetic materials are held on the surface of the drum while the non-magnetic material drops into the discharge spigot 32. The magnetic material is carried on past the opening 31a leading to the discharge spigot 3?. and is carried up to the magnetic concentrate discharge 42, where it is released. Magnetic material carried on the drum builds up and forces the released magnetic material over the magnetic concentrate discharge 42. A spray pipe 43 which extends along the drum above the magnetic concentrate discharge 42 sprays water on the drum to remove the solids.` The non-magnetic material settles into discharge spigot 32 and subsequently out through down-take pipes 27. Each downtake pipe has a flexible section 28, and a pinch clamp 29 which may be used to throttle the discharge and provides another means for controlling the pulp level in the magnetic separator, The down-take hose 28 is made of a durable rubber, neoprene or like materials.

A ilexible sampling spout 44, controlled by a pinch clamp 4S provides means for sampling the discharge from the magnetic separator at desired intervals. A fresh water line 46, controlled by a valve 47, provides a lance of fresh water directed into each down-take, which prf vides means for washing 4out the down-take with a high velocity stream of water in the event the pulp cakes or clogs the down-takes. The fresh water inlet 46 adds water to the pulp in the separator, which is another means for controlling the pulp level in the separator. The details of construction of the magnetic separators are not part of the invention per se, and the precise details of construction of the drum will not be described since such drums with their magnetic equipment are common items of commerce and may be purchased on the open market.

The magnetic separator 24 is an electro-magnetic separator, and it operates on a counter-current ow. In this ease, a rubber-covered drum 50 is mounted on the side of the spiral classifier tank 10, and a replaceable tray 51 is juxtaposed along the bottom surface of the drum, substantially enveloping the lower part of its periphery. A slat weir 52 is mounted on one end of the tank in which the drum operates which provides one means for controlling the water level of the pool in which the magnetic separator operates. With all the slats of the Weir 52 in place, the drum will operate in the high-water level 53a, while with no slats in the weir the drum will operate in the low-water line 53h. The slat Weir 52 discharges into a discharge laundei 54, discharging the overflow of the magnetic separator. The spigot 51a in the removable tray 51 discharges through multiple down-take pipes 27. A feed box 57 having a dead bed bottom 58 feeds into a feed launder 59 extending along the length of the drum. Feed from the feed launder passes through grate openings 66 into the space between the drum 50 and the removable tray 51. Electro-magnets 61 internally of the drum pick up magnetic material as it passes through the grate openings 60 and pass it upwardly along the drum beyond the field of the magnets, where it is discharged over a magnetic concentrate discharge 62. The build-up of magnetic material just past the magnetic field forces the magnetic material over the discharge 62. The discharge 62 passes around the down-pipe of the feed box 57. The non-magnetic material which is not picked up under the influence of the internal magnet 61 of the magnetic separator is discharged down through spigot 51a into multiple down-takes 27. The down-takes include a exible, tubular piece 28 and a pinch clamp 29 providing another means of controlling the pulp level of the separator. A sampling spout 44, controlled by means of the 4 pinch clamp 45, provides means for periodically taking samples. A water inlet 63 controlled by a valve 64 provides a fresh water lance or-stream of water for each of the down-take papes 27 for cleaning them out in the event of a build-up of solids in the down-take pipes, or for adding more water to the system, which provides another means of controlling the pulp level of the separator. The level of the water in the magnetic separator is somewhat above the level of the water level of the spiral classifier so that, depending on the process, the non-magnetic or the magnetic material is discharged by gravity into the dewatering spiral classifier.

In another effective application of the device according to the invention, illustrated by the Figs. 5 and 6, washed magnetic heavy media is fed to the magnetic separator 25 which separates the magnetic heavy media from the diluting non-magnetic fines. The non-magnetics are Y removed in the underflow through spigot 73, by means trol the pulp level of the separator.

of down-takes 27, each of which is equipped with a pinch clamp 29 mounted on exi'ole tubular section 28, providing one of the means of controlling the pulp level of the magnetic separator. Another means of controlling the pulp level is an adjustable overilow weir 74 which is mounted on one end of the tank in which the drum operates. The magnetic heavy media are released by the magnetic separator at the discharge 72 down chute 72a and fed into the ,classier 10, which in this application is known as Heavy Media Densier. Adjustment of the side overow weirs 21 allows control of the pool level 22 and of the dewatering deck 23, over which the spiral flight conveyor 17 discharges the dewatered and deslimed heavy media. The lifting device, or hoist, 20 permits operating the conveyor 17 in raised position which allows the use of the pool volume for surge storage. Raising or lowering of the conveyor 17 decreases or increases, respectively, the amount of heavy media returned to the circuit, thus maintaining the desired density.

There are three main controls for the operation of the magnetic separators. The rst is control of the amount of feed entering the feed boxes leading to the separators, the second is `control of the adjustable down-take pipes which discharge the non-magnetic material and thus con- The fresh water lance may also be used to control the liquid level in the drum separator. The pool in which a magnetic drum is operated may also be adjusted by means of the slat wer. The down-take pipes are adjusted to compensate for variations in feed during the operation of the drum. The fresh water inlet is, likewise, used to compensate for variations in the feed after the level of the drum separators has been established, and to control the consistency of the pulp. The level of the pulp in the spiral elassier is determined by means of the adjustable overow weirs 21, and the operation of the classifier may, in certain applications, be controlled to some extent by means of the fresh water inlets, e. g., putting in more or less fresh water with the non-magnetics discharge. These controls provide means for accurately controlling the operation of the magnetic separators so that they operate at their optimum efficiency, and the operation of the spiral classier may also be controlled independently of the drum separator so that it may, also, operate at its optimum eciency. The magnetic separators are very sensitive to the height of the liquid level in which they are operated, as well as to the particular type of pulp. It is, therefore, important that the level of the pulp in the tanks of the drum separators be closely controlled, The operation of the spiral classier may be independently adjusted for eflicient dewatering and desliming of the non-magnetics delivered to it from the magnetic separator. The operation of the spiral classifier includes dewatering and desliming the non-magnetic and magnetic product Vfrom the separator, allowing the same to `settle to the pool bottom and be conveyed out of the pool across the dewatering deck 23 to the discharge point.

The water and slirnes overflow from the classifier tank by means of the weirs on either side of the tank.

The water inlets into the underflow or spigots of the magnetic separators not only provide means for controlling the pulp level in the separator, but, also provide a means for controlling the underflow pulp density. The settling of solids in the non-magnetic pulp or underflow may be controlled by the variation of dilution of the pulp, which, also, provides a density control for the feed of mechanical classifier. The water input, therefore, provides means for selectively controlling the pulp ratios of pulp feed to the classifier, and the underflow or nonmagnetic pulp, as well as providing a means for controlling pulp level in the magnetic separator.

While the invention has been described by reference to a specific device, there is no intent to limit the invention to the precise details so described, except insofar as defined in the following claims.

We claim:

l. Apparatus for multiple stage separation of solids in liquids comprising a classifier tank for a second stage separation having three sides and sloping bottom forming a pool, mechanism for moving settled solids through the pool and along the sloping bottom to an elevated point of discharge, the tank having a feed inlet and an overflow discharge determining the liquid level in said tank, a magnetic separator mounted on one of said sides, means for delivering a pulp having a magnetic content to said separator for an initial separation of a solids constituent, -said separator having an upper discharge for magnetic material and a lower discharge for residual pulp, conduit means arranged to conduct said lower discharge to a point of discharge substantially below said separator, means for throttling the flow through said conduit so as to maintain a liquid level in said separator at a higher elevation than said pool, and means supported from said clasilied tank for directing one of said separator discharge products into the classifier pool by gravity flow for a second stage liquidsolids separation therein.

2. Apparatus for multiple stage separation of solids suspended in liquids comprising a classifier tank for a second stage separation having three sides and a sloping bottom forming a pool, mechanism for moving settled solids through the pool and along the sloping bottom to an elevated point of discharge, the tank having a feed inlet and an overflow discharge determining the liquid level in said tank, at least one magnetic separator mounted on a wall of said tank, means for delivering a pulp having a magnetic content to said separator for an initial separation of a solids constituent, said separator having an upper discharge for magnetic material and a lower discharge for residual pulp, conduit means arranged to conduct said lower discharge into said tank at a point substantially below the surface of said pool, and means for throttling the flow through said conduit means so as to maintain a liquid level in said separator at a higher elevation than said pool whereby the resulting hydrostatic head will induce a flow under pressure through said conduit and into said pool. n

3. Apparatus according to claim 2 in which the conduit means includes multiple down-take conduits.

4. Apparatus according to claim 2 in which the conduit means includes multiple down-take conduits having a flexible section, and the throttling means includes an adjustable pinch clamp on each of said flexible sections so as to throttle the flow of residual pulp from said separator.

5. Apparatus for multiple stage separation of solids suspended in liquids comprising a classifier tank for a second stage separation having three sides and a sloping bottom forming a pool, mechanism for moving settled solids through the pool and along the sloping bottom to an elevated point of discharge, the tank having a feed inlet and lan overflow discharge determining the liquid level in said tank, at least one magnetic separator mounted on a wall of said tank, means for delivering a pulp having a magnetic content to said separator for an initial separation of a solids constituent, said separator having an upper discharge for magnetic material and a lower discharge for residual pulp, conduit means for delivering material from the lower discharge into the classifier tank, means for throttling the flow of pulp through said conduit means so as to maintain a liquid level in said separator at a higher elevation than the liquid level of said pool, and discharge means for conducting the residual pump by gravity flow from said separator into the classifier pool and below the surface thereof for a second stage liquid-solids separation therein.

6. Apparatus for multiple stage separation of finely divided solids suspended in carrier liquids comprising a mechanical classifier tank for a second stage separation having three sides and a sloping bottom forming a pool, mechanism for moving settled solids through the pool and along the bottom to an elevated point of discharge, the tank having a feed inlet and an adjustable overflow discharge determining the liquid level therein, at least one magnetic separator mounted on a wall of said tank, means for delivering a pulp having a magnetic content to said separator for an initial separation of the magnetic content of said pulp, said separator having an yupper magnetic discharge and a lower discharge for residual pulp, multiple down-takes arranged to convey said residual pulp by gravity flow from said separator -to said tank substantially below the surface of the pool therein, means on each of the down-takes for throttling the llow of pulp through said down-takes so as to maintain the level of liquid in said separator at a higher level than the liquid level of said pool, an adjustable weir overflow for said separator for maintaining the level of liquid therein, and a water inlet into said lower discharge for introducing water into said separator for maintaining the level of liquid therein.

7. Apparatus for multiple stage separation of finely divided solids suspended in carrier liquids comprising a classifier tank for a second stage separation having three sides and a sloping bottom forming a pool, a spiral flight conveyor for moving settled solids through the pool and along the sloping bottom to an elevated point of discharge, the tank having a feed inlet and an adjustable overflow discharge determining the liquid level therein, a pair of magnetic separators mounted on opposite walls of said tank, means for delivering a pulp feed having a magnetic content to each of said separators for an initial separation of the magnetic content of said pulp, said separators having an upper magnetic discharge and a lower discharge for residual pulp, multiple down-take conduits from each of said separators arranged to convey residual pulp by gravity flow from the separators to said tank substantially below the surface of the pool therein, adjustable pinch clamp means on each said down-take conduits for selectively throttling the flow of pulp therethrough so as to maintain the liquid level in said separators at a higher level than the liquid level of said pool, an adjustable overllow for each said separator for maintaining the level therein, and a water inlet directed into each of said down-take conduits for introducing water into said separator for maintaining the liquid level therein.

References Cited in the file of this patent UNITED STATES PATENTS 

